Rheostat



(No Model.) 2 SheetsShet 1.

S. H. SHORT.

RHEOSTAT. No. 599,803. Patented Mar. 1,1898.

(No Model.) 2 Sheets-Sheet 2.

S. H. SHORT. RHEOSTAT.

No. 599,803. Patented Mar. 1,1898.

UNITED STATES PATENT OFFICE.

SIDNEY H. SHORT, OF CLEVELAND, OHIO.

RHEOSTAT.

SPECIFICATION forming part of Letters Patent No 599,803, dated March 1, 1898.

Application filed May 14, 1897. Serial No. 636,474. (No model.)

T0 to whom it may concern:

Be it known that I, SIDNEY H. SHORT, a citizen of the United States, residing at Cleveland, in the county of Ouyahoga and State of Ohio, have invented a new and useful Rheostat, of which the following is a specification.

This invention relates to rheostats.

The object of the invention is to provide a rheostat particularly adapted for use in connection with street-rail way motors and wherein any desirable range of variation in resistance can be secured. 4

The further object of the invention is to provide a rheostat of simple and improved construction and thoroughly efficient in operation.

The invention consists, substantially, in the construction, combination, location, and relative arrangement of parts, all as will be more fully hereinafter set forth, as shown in the accompanying drawings and finally specifically pointed out in the appended claims.

Referring to the accompanying drawings and to the various views and reference signs appearing thereon, Figure 1 is a View in side elevation of a rheostat embodying my invention, part of the casing being broken away and part of the rheostat-sections and the frame being in vertical central section. Fig. 2 is an end view of one of the rheostat-sections. Figs. 3 and at are respectively a side elevation and plan view of the rheostat-section terminal. Fig. 5 is a view in perspective of the terminal plate. Fig. 6 is a broken sectional view, in side elevation, of the spider-hub on the line 6 6, looking in the direction of the arrows.

Heretofore it has been the custom to form the rheostats employed in connection with street-railway motors by placing alternate pieces of sheet-iron and asbestos in layers, having certain portions of the iron exposed, at which points such pieces of sheet-iron are electrically connected together in order to permit the current to flow from onesheet to another. This arrangement is objectionable for various reasons. The most serious objection is that in the ordinary rheostat only two, or at most three, variations in the resistance of the motor-circuit can be had. Another and a serious objection is the cost and complexity of such construction.

It is the purpose of my invention to avoid the objections noted and to provide a construction of rheostat or resistance-box for use in connection with street-railway motors wherein any desired range of variation in the motorcircuit resistance can be secured easily and by a simple and efficient construction.

I have shown in the accompanying drawings a construction of rheostat embodying my invention and which is composed of a number of sect-ions suitably assembled and coupled up, as will presently more fully appear, each section comprising a hub A, having spokes B radiating therefrom and carrying forked arms 0, the spokes B and arms 0 being suitably connected, if desired, by means of a rim D, the whole forming a spider or reel adapted to receive and support in the forked arms 0 thereof the resistance material. The rim D may be suitably shaped in the outer periphery thereof to receive a strip E of mica or other suitable insulating material. The resistance material comprises a strip of iron and is applied to the spider by Winding the same thereon. This is accomplished by placing the strip of iron with its end F bent out therefrom a sufficient length to make electrical connection with the terminal of the next adjacent section of the rheostat. The hub A may be slipped on the spindle of a lathe or other suitable device whereby it may be rotated, and the strip of iron, with its end F bent or deflected outwardly therefrom and with a superposed strip of asbestos, is secured in any suitable manner to the spider, and by imparting a rotation to the spider the strips of iron and asbestos are tightly wound upon such spider in spiral convolutions or coils until the desired amount of iron is reeled or coiled thereon. Before beginning the winding operation, however, and in order to thoroughly insulate the resistan ce-iron strip from the spider, which in practice I prefer to make of cast-iron, I place the troughs or strips G, of mica or. other suitable insulating material, within the arms 0. These strips, together with the insulating-strip E, serve to efficiently insulate the resistance-iron from the support ing-spider. hen the section has been completedthat is, when a sufficient amount of resistance-iron has been coiled thereonthe end of the iron coil or strip may be coupled or connected electrically to a suitable terminal in any convenient or desirable manner. I have shown an exceedingly simple and efficient terminal for the purpose desired, wherein I provide a strap H, having a slot or opening J in one end thereof, through which slot or opening I pass the strip of insulated iron. I then bend the end of such strip of iron back upon itself and around the surface of the coil and over the other end K of strap H. This end of the strap is provided with projecting lugs L on opposite sides thereof, and at the extreme end is provided with a hook M. Before passing the strip of resistance-iron over the end K of the strap I fold such strip around a plate N, as clearly shown in Fig. 2, and I' then place the plate N in position upon the portion K of strap H, with the end of said plate abutting against the shoulder M. The lugs L are then bent tightly down over the plate N and the end of the strip of resistanceiron, thereby effecting an efficient securing of the end of such strip to the terminal H. This terminal is provided with two sockets, one of which is adapted to receive the end F of the coil of resistance-iron forming the next adjacent section of the rheostat, such end F being held therein by means of a suitable setscrew 0 or in any other suitable or convenient manner. The other socket in the strap H is adapted to receive the terminal P of the motor-circuit, such terminal being held therein by means of set-screws Q or in any other,

convenient manner.

I Will now describe the arrangement for assembling the several sections of the rheostat.

R designates a supporting-rod which in practice may comprise a section of gas-pipe supported at the ends thereof in brackets or end cases S S, adapted to be bolted or otherwise suitably secured to or mounted on the carbody or truck-frame in any suitable or convenient position, the rod R being held in place by means of set-nuts T, mounted on the threaded ends thereof and outside of the end casings S S, spring-washers U being interposed between said nuts and the casings. Before the end casings S S are placed upon the ends of the supporting-rod R the hubs A of the several sections of the rheostat are slipped over such rod and crowded upon each other until the desired number of sections have been placed thereon. The end casings are then slipped over the ends of the rod and the nuts T, with the spring-washers U, are turned up to clamp the sections in place and between the end casings S S", it being understood that the projecting end F of the strip of' insulatingiron in each rheostat-section is electrically connected to the terminal H of the next ad j acent section. In order to prevent any relative rotation of the rheostat-spiders upon the support R, I provide the hub A of each section on one side thereof with a projection V and on the other side thereof with a depression or seat IV, and I provide similarprojections and depressions on the opposing faces of the end sections S S, the projection V of the one section adapted to be received in the seats or depressions W of the next adjacent section and the last section at each end being similarly locked or engaged with the end casings S S.

From the foregoing description it will be seen that I provide an exceedingly simple and efficient resistance-box or rheostat for use in connection with street-railway motors, one that is economical in manufacture and efficient and wherein any desired variation in the resistance of the motor-circuit may be secured by changing the terminals P of the motor-circuit from one to any one of the others of the sections of the rheostat, and hence the resistance in the motor-circuit may be made as large or as small as may be desired by thus varying the connection of the motor-terminals P and without the necessity of removing a portion of the rheostat laminations or plates, as has been the custom heretofore. By reason of the construction of spider for supporting the resistance-iron as above described I secure an ample ventilation of the rheostat.

The entire resistance-box,constructed and as-- sembled as above described, is arranged to be received in an inclosing casing A in the usual manner, with the terminals H of each section projecting therefrom in order to facilitate the attachment thereto of the motor-terminals P. A convenient arrangement of the casin g A is shown, wherein the end casings S S are suitably grooved on their opposed faces, as at B, Fig. 1, to receive the ends of the casing-shell, and when the end casings are clamped toward each other by the nuts T in order to clamp the rheostat-sections in place they also thereby effect a clamping of the casing A.

I desire it to be understood that many variations and changes in the details of construction,arrangement, and location of parts would readily suggest themselves to persons skilled in the art and still fall within the spirit and scope of my invention. I do not desire, therefore, to be limited or restricted to the exact details of construction and arrangement shown and described; but,

Having now set forth the nature and object of my invention and a form of apparatus embodying the same and having described the construction, function, and mode of operation thereof, what I claim as new and useful and of my own invention, and desire to secure by Letters Patent of the United States, is-

1. In a rheostat for street-railwaymotors, a spider having radial arms adapted to receive the resistance material in spiral convolute layers therebetween, and means for attaching the motor-circuit terminals to such resistance material, as and for the purpose set forth.

v2. In a rheostat for electric motors, a spider having radial arms adapted to receive the resistance material in spiral convolute layers therebetween, means for insulating such resistance material from such spider, and means ICC for connecting the motor-circuit terminals to i such resistance material, as and for the purpose set forth.

3. In a rheostat for street-railway motors, a spider comprising a hub, forked arms carried thereby, the resistance material adapted to be carried by said forked arms, and means for connecting the terminals of the motor-circuit to said resistance material, as and for the purpose set forth.

t. In a rheostat for street-car motors, a spider comprising a hub, forked arms radiating therefrom ,the resistance material adapted to be received in said forked arms in spiral convolutions, a strap for securing the end of the resistance material, and means for attaching the motor-circuit terminal to such strap, as and for the purpose set forth.

5. In a rheostat for street-railway motors, a strip of resistance material formed in spiral coils, a strap having a slot through which the end of the material is passed, and means for securing such end to such strap at the opposite side thereof, and means for securing the motor-circuit terminal to such strap, as and for the purpose set forth.

6. A rheostat for street-railway motors consisting of a plurality of sections, each section comprising a hub havin radial arms adapted to receive therebetween a spirally-wound strip of resistance material, the resistance material of one section being in electrical connection with the next adjacent section, each section having means for attaching the ends of the motor-circuit thereto, as and for the purpose set forth.

7. A rheostat for street-railway motors comprising a series of sections electrically connected together, each section consisting of a hub having radially-arranged forked arms adapted to receive therebetween a spirallywound strip of resistance material, and a strap for securing the end of the strip of each section, said strap adapted to receive the terminal of the motor-circuit, as and for the purpose set forth.

8. In a rheostat for street-railway motors, a supporting-bar, a series of spider-hubs having radially-arranged forked arms mounted on said bar, a spirally-wound coil of resistance material arranged between the forked arms of each spider-hub, the resistance material of one hub being electrically connected to that of the adjacent hub, and means for preventing the rotation of said hubs on said bar, each section having means adapted to receive the terminal of the motor-circuit, as and for the purpose set forth.

9. In a rheostat for street-railway motors, a supporting-bar, a series of spider-h ubs having radially-arranged forked arms mounted on said bar, a spirally-wound coil of resistance material arranged between the forked arms of each spider-hub, the resistance material of one hub being electrically connected to that of the adjacent hub, end casings mounted on the ends of said bar, and means for clamping said hubs between said end casings, as and for the purpose set forth.

10. In a rheostat for street-railway motors, a supporting-bar, spider-hubs having radially-arranged forked arms mounted on said bar, a spirally-wound coil of resistance material arranged between the forked arms of each spider-hub, the resistance material of one hub being electrically connected to that of the adjacent hub, each section provided with a socket in which the motor-circuit terminals are inserted, means for clamping said sections upon said bar, and a casing adapted to inclose said sections, as and for the purpose set forth.

11. In a rheostat for street-railway motors, a supporting-bar, a series of spiders mounted on said bar, the resistance material of one spider in electrical connection with the resistance material carried by the next adjacent spider, means for attaching the motorcircuit terminal to the resistance material of each spider, the hubs of said spiders provided with interlocking grooves or depressions, as and for the purpose set forth.

12. In a rheostat for street-railway motors, a support, sections of resistance material electrically connected together and mounted on said support, end casings also mounted 011 said support and adapted to clamp said sections together, said end casings being grooved on the opposed faces thereof, and an inclosin g shield for said sections having the ends thereof arranged to be received in the grooves in said end casings, as and for the purpose set forth.

13. In a rheostat for street-railway motors, a spider comprising a hub, spokes radiating therefrom, and a rim supported by said spokes, a strip of resistance material adapted to be Wound on said rim but insulated therefrom, and means for attaching the motorterminal to said resistance material, as and for the purpose set forth.

14. A rheostat-section comprising a spirallywound strip of resistance material, a strap having a slot at one end and flanges at the other end, the end of the strip of resistance material adapted to be passed through said slot and reversely bent upon itself and secured by said flanges to the opposite end of said strap, said strap adapted to receive the terminal of the motor-circuit, as and for the purpose set forth.

15. A rheostat-section comprising a strip of resistance material spirally wound upon itself, a strap for securing the end of said spiral, said strap having a slot at one end and a hooked portion at the other end, the end of the strip of resistance materal adapted to be passed through said slot and then bent back upon itself, a securing-plate around which the end of said strip is passed, and means for securing said plate to the hooked end of said strap, and means for attaching the motorterminal to said strap, as and for the purpose set forth.

10. In a rheostat-section, a strap having sockets, the end of the motor-circuit adapted to be received in one of said sockets, and-the end of the resistance material of the next adjacent section adapted to be received in the other of said sockets, and means for securing the end of the resistance material to said strap, as and for the purpose set forth. I

17. In a rheostat-seotion, a spider comprising a hub, spokes radiating therefrom, a rim supported by said spokes and forked arms, a strip of insulating material arranged on said rim, and insulating-pockets arranged in said forked arms, a strip of resistance material SIDNEY H. SHORT.

Attest:

M. A. KENSINGER, JOHN J. BEVER. 

